arch/sparc64/kernel/process.c

   1 /*  $Id: process.c,v 1.131 2002/02/09 19:49:30 davem Exp $
   2  *  arch/sparc64/kernel/process.c
   3  *
   4  *  Copyright (C) 1995, 1996 David S. Miller (davem@caip.rutgers.edu)
   5  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
   6  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   7  */
   8
   9 /*
  10  * This file handles the architecture-dependent parts of process handling..
  11  */
  12
  13 #include <stdarg.h>
  14
  15 #include <linux/config.h>
  16 #include <linux/errno.h>
  17 #include <linux/module.h>
  18 #include <linux/sched.h>
  19 #include <linux/kernel.h>
  20 #include <linux/kallsyms.h>
  21 #include <linux/mm.h>
  22 #include <linux/smp.h>
  23 #include <linux/smp_lock.h>
  24 #include <linux/stddef.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/slab.h>
  27 #include <linux/user.h>
  28 #include <linux/a.out.h>
  29 #include <linux/config.h>
  30 #include <linux/reboot.h>
  31 #include <linux/delay.h>
  32 #include <linux/compat.h>
  33 #include <linux/init.h>
  34
  35 #include <asm/oplib.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/system.h>
  38 #include <asm/page.h>
  39 #include <asm/pgalloc.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/processor.h>
  42 #include <asm/pstate.h>
  43 #include <asm/elf.h>
  44 #include <asm/fpumacro.h>
  45 #include <asm/head.h>
  46 #include <asm/cpudata.h>
  47 #include <asm/unistd.h>
  48
  49 /* #define VERBOSE_SHOWREGS */
  50
  51 /*
  52  * Nothing special yet...
  53  */
  54 void default_idle(void)
  55 {
  56 }
  57
  58 #ifndef CONFIG_SMP
  59
  60 /*
  61  * the idle loop on a Sparc... ;)
  62  */
  63 int cpu_idle(void)
  64 {
  65         if (current->pid != 0)
  66                 return -EPERM;
  67
  68         /* endless idle loop with no priority at all */
  69         for (;;) {
  70                 /* If current->work.need_resched is zero we should really
  71                  * setup for a system wakup event and execute a shutdown
  72                  * instruction.
  73                  *
  74                  * But this requires writing back the contents of the
  75                  * L2 cache etc. so implement this later. -DaveM
  76                  */
  77                 while (!need_resched())
  78                         barrier();
  79
  80                 schedule();
  81                 check_pgt_cache();
  82         }
  83         return 0;
  84 }
  85
  86 #else
  87
  88 /*
  89  * the idle loop on a UltraMultiPenguin...
  90  */
  91 #define idle_me_harder()        (cpu_data(smp_processor_id()).idle_volume += 1)
  92 #define unidle_me()             (cpu_data(smp_processor_id()).idle_volume = 0)
  93 int cpu_idle(void)
  94 {
  95         set_thread_flag(TIF_POLLING_NRFLAG);
  96         while(1) {
  97                 if (need_resched()) {
  98                         unidle_me();
  99                         clear_thread_flag(TIF_POLLING_NRFLAG);
 100                         schedule();
 101                         set_thread_flag(TIF_POLLING_NRFLAG);
 102                         check_pgt_cache();
 103                 }
 104                 idle_me_harder();
 105
 106                 /* The store ordering is so that IRQ handlers on
 107                  * other cpus see our increasing idleness for the buddy
 108                  * redistribution algorithm.  -DaveM
 109                  */
 110                 membar("#StoreStore | #StoreLoad");
 111         }
 112 }
 113
 114 #endif
 115
 116 extern char reboot_command [];
 117
 118 extern void (*prom_palette)(int);
 119 extern void (*prom_keyboard)(void);
 120
 121 void machine_halt(void)
 122 {
 123         if (!serial_console && prom_palette)
 124                 prom_palette (1);
 125         if (prom_keyboard)
 126                 prom_keyboard();
 127         prom_halt();
 128         panic("Halt failed!");
 129 }
 130
 131 EXPORT_SYMBOL(machine_halt);
 132
 133 void machine_alt_power_off(void)
 134 {
 135         if (!serial_console && prom_palette)
 136                 prom_palette(1);
 137         if (prom_keyboard)
 138                 prom_keyboard();
 139         prom_halt_power_off();
 140         panic("Power-off failed!");
 141 }
 142
 143 void machine_restart(char * cmd)
 144 {
 145         char *p;
 146
 147         p = strchr (reboot_command, '\n');
 148         if (p) *p = 0;
 149         if (!serial_console && prom_palette)
 150                 prom_palette (1);
 151         if (prom_keyboard)
 152                 prom_keyboard();
 153         if (cmd)
 154                 prom_reboot(cmd);
 155         if (*reboot_command)
 156                 prom_reboot(reboot_command);
 157         prom_reboot("");
 158         panic("Reboot failed!");
 159 }
 160
 161 EXPORT_SYMBOL(machine_restart);
 162
 163 static void show_regwindow32(struct pt_regs *regs)
 164 {
 165         struct reg_window32 __user *rw;
 166         struct reg_window32 r_w;
 167         mm_segment_t old_fs;
 168
 169         __asm__ __volatile__ ("flushw");
 170         rw = (struct reg_window32 __user *)((long)(unsigned)regs->u_regs[14]);
 171         old_fs = get_fs();
 172         set_fs (USER_DS);
 173         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 174                 set_fs (old_fs);
 175                 return;
 176         }
 177
 178         set_fs (old_fs);
 179         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 180                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 181                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 182                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 183         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 184                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 185                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 186                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 187 }
 188
 189 static void show_regwindow(struct pt_regs *regs)
 190 {
 191         struct reg_window __user *rw;
 192         struct reg_window *rwk;
 193         struct reg_window r_w;
 194         mm_segment_t old_fs;
 195
 196         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 197                 __asm__ __volatile__ ("flushw");
 198                 rw = (struct reg_window __user *)
 199                         (regs->u_regs[14] + STACK_BIAS);
 200                 rwk = (struct reg_window *)
 201                         (regs->u_regs[14] + STACK_BIAS);
 202                 if (!(regs->tstate & TSTATE_PRIV)) {
 203                         old_fs = get_fs();
 204                         set_fs (USER_DS);
 205                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 206                                 set_fs (old_fs);
 207                                 return;
 208                         }
 209                         rwk = &r_w;
 210                         set_fs (old_fs);
 211                 }
 212         } else {
 213                 show_regwindow32(regs);
 214                 return;
 215         }
 216         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 217                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 218         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 219                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 220         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 221                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 222         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 223                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 224         if (regs->tstate & TSTATE_PRIV)
 225                 print_symbol("I7: <%s>\n", rwk->ins[7]);
 226 }
 227
 228 void show_stackframe(struct sparc_stackf *sf)
 229 {
 230         unsigned long size;
 231         unsigned long *stk;
 232         int i;
 233
 234         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n"
 235                "l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 236                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
 237                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
 238         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n"
 239                "i4: %016lx i5: %016lx fp: %016lx ret_pc: %016lx\n",
 240                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
 241                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
 242         printk("sp: %016lx x0: %016lx x1: %016lx x2: %016lx\n"
 243                "x3: %016lx x4: %016lx x5: %016lx xx: %016lx\n",
 244                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
 245                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
 246                sf->xxargs[0]);
 247         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
 248         size -= STACKFRAME_SZ;
 249         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
 250         i = 0;
 251         do {
 252                 printk("s%d: %016lx\n", i++, *stk++);
 253         } while ((size -= sizeof(unsigned long)));
 254 }
 255
 256 void show_stackframe32(struct sparc_stackf32 *sf)
 257 {
 258         unsigned long size;
 259         unsigned *stk;
 260         int i;
 261
 262         printk("l0: %08x l1: %08x l2: %08x l3: %08x\n",
 263                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3]);
 264         printk("l4: %08x l5: %08x l6: %08x l7: %08x\n",
 265                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
 266         printk("i0: %08x i1: %08x i2: %08x i3: %08x\n",
 267                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3]);
 268         printk("i4: %08x i5: %08x fp: %08x ret_pc: %08x\n",
 269                sf->ins[4], sf->ins[5], sf->fp, sf->callers_pc);
 270         printk("sp: %08x x0: %08x x1: %08x x2: %08x\n"
 271                "x3: %08x x4: %08x x5: %08x xx: %08x\n",
 272                sf->structptr, sf->xargs[0], sf->xargs[1],
 273                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
 274                sf->xxargs[0]);
 275         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
 276         size -= STACKFRAME32_SZ;
 277         stk = (unsigned *)((unsigned long)sf + STACKFRAME32_SZ);
 278         i = 0;
 279         do {
 280                 printk("s%d: %08x\n", i++, *stk++);
 281         } while ((size -= sizeof(unsigned)));
 282 }
 283
 284 #ifdef CONFIG_SMP
 285 static spinlock_t regdump_lock = SPIN_LOCK_UNLOCKED;
 286 #endif
 287
 288 void __show_regs(struct pt_regs * regs)
 289 {
 290 #ifdef CONFIG_SMP
 291         unsigned long flags;
 292
 293         /* Protect against xcall ipis which might lead to livelock on the lock */
 294         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 295                              "wrpr      %0, %1, %%pstate"
 296                              : "=r" (flags)
 297                              : "i" (PSTATE_IE));
 298         spin_lock(&regdump_lock);
 299 #endif
 300         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 301                regs->tpc, regs->tnpc, regs->y, print_tainted());
 302         print_symbol("TPC: <%s>\n", regs->tpc);
 303         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 304                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 305                regs->u_regs[3]);
 306         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 307                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 308                regs->u_regs[7]);
 309         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 310                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 311                regs->u_regs[11]);
 312         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 313                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 314                regs->u_regs[15]);
 315         print_symbol("RPC: <%s>\n", regs->u_regs[15]);
 316         show_regwindow(regs);
 317 #ifdef CONFIG_SMP
 318         spin_unlock(&regdump_lock);
 319         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 320                              : : "r" (flags));
 321 #endif
 322 }
 323
 324 #ifdef VERBOSE_SHOWREGS
 325 static void idump_from_user (unsigned int *pc)
 326 {
 327         int i;
 328         int code;
 329
 330         if((((unsigned long) pc) & 3))
 331                 return;
 332
 333         pc -= 3;
 334         for(i = -3; i < 6; i++) {
 335                 get_user(code, pc);
 336                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
 337                 pc++;
 338         }
 339         printk("\n");
 340 }
 341 #endif
 342
 343 void show_regs(struct pt_regs *regs)
 344 {
 345 #ifdef VERBOSE_SHOWREGS
 346         extern long etrap, etraptl1;
 347 #endif
 348         __show_regs(regs);
 349 #ifdef CONFIG_SMP
 350         {
 351                 extern void smp_report_regs(void);
 352
 353                 smp_report_regs();
 354         }
 355 #endif
 356
 357 #ifdef VERBOSE_SHOWREGS
 358         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
 359             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
 360             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
 361                 printk ("*********parent**********\n");
 362                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
 363                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
 364                 printk ("*********endpar**********\n");
 365         }
 366 #endif
 367 }
 368
 369 void show_regs32(struct pt_regs32 *regs)
 370 {
 371         printk("PSR: %08x PC: %08x NPC: %08x Y: %08x    %s\n", regs->psr,
 372                regs->pc, regs->npc, regs->y, print_tainted());
 373         printk("g0: %08x g1: %08x g2: %08x g3: %08x ",
 374                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 375                regs->u_regs[3]);
 376         printk("g4: %08x g5: %08x g6: %08x g7: %08x\n",
 377                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 378                regs->u_regs[7]);
 379         printk("o0: %08x o1: %08x o2: %08x o3: %08x ",
 380                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 381                regs->u_regs[11]);
 382         printk("o4: %08x o5: %08x sp: %08x ret_pc: %08x\n",
 383                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 384                regs->u_regs[15]);
 385 }
 386
 387 unsigned long thread_saved_pc(struct task_struct *tsk)
 388 {
 389         struct thread_info *ti = tsk->thread_info;
 390         unsigned long ret = 0xdeadbeefUL;
 391
 392         if (ti && ti->ksp) {
 393                 unsigned long *sp;
 394                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 395                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 396                     sp[14]) {
 397                         unsigned long *fp;
 398                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 399                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 400                                 ret = fp[15];
 401                 }
 402         }
 403         return ret;
 404 }
 405
 406 /* Free current thread data structures etc.. */
 407 void exit_thread(void)
 408 {
 409         struct thread_info *t = current_thread_info();
 410
 411         if (t->utraps) {
 412                 if (t->utraps[0] < 2)
 413                         kfree (t->utraps);
 414                 else
 415                         t->utraps[0]--;
 416         }
 417
 418         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 419                 t->user_cntd0 = t->user_cntd1 = NULL;
 420                 t->pcr_reg = 0;
 421                 write_pcr(0);
 422         }
 423 }
 424
 425 void flush_thread(void)
 426 {
 427         struct thread_info *t = current_thread_info();
 428
 429         if (t->flags & _TIF_ABI_PENDING)
 430                 t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
 431
 432         if (t->task->mm) {
 433                 unsigned long pgd_cache = 0UL;
 434                 if (test_thread_flag(TIF_32BIT)) {
 435                         struct mm_struct *mm = t->task->mm;
 436                         pgd_t *pgd0 = &mm->pgd[0];
 437
 438                         if (pgd_none(*pgd0)) {
 439                                 pmd_t *page = pmd_alloc_one_fast(NULL, 0);
 440                                 if (!page)
 441                                         page = pmd_alloc_one(NULL, 0);
 442                                 pgd_set(pgd0, page);
 443                         }
 444                         pgd_cache = ((unsigned long) pgd_val(*pgd0)) << 11UL;
 445                 }
 446                 __asm__ __volatile__("stxa %0, [%1] %2\n\t"
 447                                      "membar #Sync"
 448                                      : /* no outputs */
 449                                      : "r" (pgd_cache),
 450                                      "r" (TSB_REG),
 451                                      "i" (ASI_DMMU));
 452         }
 453         set_thread_wsaved(0);
 454
 455         /* Turn off performance counters if on. */
 456         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 457                 t->user_cntd0 = t->user_cntd1 = NULL;
 458                 t->pcr_reg = 0;
 459                 write_pcr(0);
 460         }
 461
 462         /* Clear FPU register state. */
 463         t->fpsaved[0] = 0;
 464
 465         if (get_thread_current_ds() != ASI_AIUS)
 466                 set_fs(USER_DS);
 467
 468         /* Init new signal delivery disposition. */
 469         clear_thread_flag(TIF_NEWSIGNALS);
 470 }
 471
 472 /* It's a bit more tricky when 64-bit tasks are involved... */
 473 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 474 {
 475         unsigned long fp, distance, rval;
 476
 477         if (!(test_thread_flag(TIF_32BIT))) {
 478                 csp += STACK_BIAS;
 479                 psp += STACK_BIAS;
 480                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 481                 fp += STACK_BIAS;
 482         } else
 483                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 484
 485         /* Now 8-byte align the stack as this is mandatory in the
 486          * Sparc ABI due to how register windows work.  This hides
 487          * the restriction from thread libraries etc.  -DaveM
 488          */
 489         csp &= ~7UL;
 490
 491         distance = fp - psp;
 492         rval = (csp - distance);
 493         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 494                 rval = 0;
 495         else if (test_thread_flag(TIF_32BIT)) {
 496                 if (put_user(((u32)csp),
 497                              &(((struct reg_window32 __user *)rval)->ins[6])))
 498                         rval = 0;
 499         } else {
 500                 if (put_user(((u64)csp - STACK_BIAS),
 501                              &(((struct reg_window __user *)rval)->ins[6])))
 502                         rval = 0;
 503                 else
 504                         rval = rval - STACK_BIAS;
 505         }
 506
 507         return rval;
 508 }
 509
 510 /* Standard stuff. */
 511 static inline void shift_window_buffer(int first_win, int last_win,
 512                                        struct thread_info *t)
 513 {
 514         int i;
 515
 516         for (i = first_win; i < last_win; i++) {
 517                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 518                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 519                        sizeof(struct reg_window));
 520         }
 521 }
 522
 523 void synchronize_user_stack(void)
 524 {
 525         struct thread_info *t = current_thread_info();
 526         unsigned long window;
 527
 528         flush_user_windows();
 529         if ((window = get_thread_wsaved()) != 0) {
 530                 int winsize = sizeof(struct reg_window);
 531                 int bias = 0;
 532
 533                 if (test_thread_flag(TIF_32BIT))
 534                         winsize = sizeof(struct reg_window32);
 535                 else
 536                         bias = STACK_BIAS;
 537
 538                 window -= 1;
 539                 do {
 540                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 541                         struct reg_window *rwin = &t->reg_window[window];
 542
 543                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 544                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 545                                 set_thread_wsaved(get_thread_wsaved() - 1);
 546                         }
 547                 } while (window--);
 548         }
 549 }
 550
 551 void fault_in_user_windows(void)
 552 {
 553         struct thread_info *t = current_thread_info();
 554         unsigned long window;
 555         int winsize = sizeof(struct reg_window);
 556         int bias = 0;
 557
 558         if (test_thread_flag(TIF_32BIT))
 559                 winsize = sizeof(struct reg_window32);
 560         else
 561                 bias = STACK_BIAS;
 562
 563         flush_user_windows();
 564         window = get_thread_wsaved();
 565
 566         if (window != 0) {
 567                 window -= 1;
 568                 do {
 569                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 570                         struct reg_window *rwin = &t->reg_window[window];
 571
 572                         if (copy_to_user((char __user *)sp, rwin, winsize))
 573                                 goto barf;
 574                 } while (window--);
 575         }
 576         set_thread_wsaved(0);
 577         return;
 578
 579 barf:
 580         set_thread_wsaved(window + 1);
 581         do_exit(SIGILL);
 582 }
 583
 584 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 585                               unsigned long stack_start,
 586                               struct pt_regs *regs,
 587                               unsigned long stack_size)
 588 {
 589         int __user *parent_tid_ptr, *child_tid_ptr;
 590
 591 #ifdef CONFIG_COMPAT
 592         if (test_thread_flag(TIF_32BIT)) {
 593                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 594                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 595         } else
 596 #endif
 597         {
 598                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 599                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 600         }
 601
 602         return do_fork(clone_flags, stack_start,
 603                        regs, stack_size,
 604                        parent_tid_ptr, child_tid_ptr);
 605 }
 606
 607 /* Copy a Sparc thread.  The fork() return value conventions
 608  * under SunOS are nothing short of bletcherous:
 609  * Parent -->  %o0 == childs  pid, %o1 == 0
 610  * Child  -->  %o0 == parents pid, %o1 == 1
 611  */
 612 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 613                 unsigned long unused,
 614                 struct task_struct *p, struct pt_regs *regs)
 615 {
 616         struct thread_info *t = p->thread_info;
 617         char *child_trap_frame;
 618
 619 #ifdef CONFIG_DEBUG_SPINLOCK
 620         p->thread.smp_lock_count = 0;
 621         p->thread.smp_lock_pc = 0;
 622 #endif
 623
 624         p->set_child_tid = p->clear_child_tid = NULL;
 625
 626         /* Calculate offset to stack_frame & pt_regs */
 627         child_trap_frame = ((char *)t) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
 628         memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
 629
 630         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 631                 _TIF_NEWCHILD |
 632                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 633         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 634         t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf));
 635         t->fpsaved[0] = 0;
 636
 637         if (regs->tstate & TSTATE_PRIV) {
 638                 /* Special case, if we are spawning a kernel thread from
 639                  * a userspace task (via KMOD, NFS, or similar) we must
 640                  * disable performance counters in the child because the
 641                  * address space and protection realm are changing.
 642                  */
 643                 if (t->flags & _TIF_PERFCTR) {
 644                         t->user_cntd0 = t->user_cntd1 = NULL;
 645                         t->pcr_reg = 0;
 646                         t->flags &= ~_TIF_PERFCTR;
 647                 }
 648                 t->kregs->u_regs[UREG_FP] = t->ksp;
 649                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 650                 flush_register_windows();
 651                 memcpy((void *)(t->ksp + STACK_BIAS),
 652                        (void *)(regs->u_regs[UREG_FP] + STACK_BIAS),
 653                        sizeof(struct sparc_stackf));
 654                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 655                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 656         } else {
 657                 if (t->flags & _TIF_32BIT) {
 658                         sp &= 0x00000000ffffffffUL;
 659                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 660                 }
 661                 t->kregs->u_regs[UREG_FP] = sp;
 662                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 663                 if (sp != regs->u_regs[UREG_FP]) {
 664                         unsigned long csp;
 665
 666                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 667                         if (!csp)
 668                                 return -EFAULT;
 669                         t->kregs->u_regs[UREG_FP] = csp;
 670                 }
 671                 if (t->utraps)
 672                         t->utraps[0]++;
 673         }
 674
 675         /* Set the return value for the child. */
 676         t->kregs->u_regs[UREG_I0] = current->pid;
 677         t->kregs->u_regs[UREG_I1] = 1;
 678
 679         /* Set the second return value for the parent. */
 680         regs->u_regs[UREG_I1] = 0;
 681
 682         if (clone_flags & CLONE_SETTLS)
 683                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 684
 685         return 0;
 686 }
 687
 688 /*
 689  * This is the mechanism for creating a new kernel thread.
 690  *
 691  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 692  * who haven't done an "execve()") should use this: it will work within
 693  * a system call from a "real" process, but the process memory space will
 694  * not be free'd until both the parent and the child have exited.
 695  */
 696 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 697 {
 698         long retval;
 699
 700         /* If the parent runs before fn(arg) is called by the child,
 701          * the input registers of this function can be clobbered.
 702          * So we stash 'fn' and 'arg' into global registers which
 703          * will not be modified by the parent.
 704          */
 705         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 706                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 707                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 708                              "mov %2, %%o0\n\t"    /* Clone flags. */
 709                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 710                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 711                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 712                              " mov %%o0, %0\n\t"
 713                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 714                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 715                              "mov %3, %%g1\n\t"
 716                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 717                              /* Notreached by child. */
 718                              "1:" :
 719                              "=r" (retval) :
 720                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 721                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 722                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 723         return retval;
 724 }
 725
 726 /*
 727  * fill in the user structure for a core dump..
 728  */
 729 void dump_thread(struct pt_regs * regs, struct user * dump)
 730 {
 731         /* Only should be used for SunOS and ancient a.out
 732          * SparcLinux binaries...  Not worth implementing.
 733          */
 734         memset(dump, 0, sizeof(struct user));
 735 }
 736
 737 typedef struct {
 738         union {
 739                 unsigned int    pr_regs[32];
 740                 unsigned long   pr_dregs[16];
 741         } pr_fr;
 742         unsigned int __unused;
 743         unsigned int    pr_fsr;
 744         unsigned char   pr_qcnt;
 745         unsigned char   pr_q_entrysize;
 746         unsigned char   pr_en;
 747         unsigned int    pr_q[64];
 748 } elf_fpregset_t32;
 749
 750 /*
 751  * fill in the fpu structure for a core dump.
 752  */
 753 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 754 {
 755         unsigned long *kfpregs = current_thread_info()->fpregs;
 756         unsigned long fprs = current_thread_info()->fpsaved[0];
 757
 758         if (test_thread_flag(TIF_32BIT)) {
 759                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 760
 761                 if (fprs & FPRS_DL)
 762                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 763                                sizeof(unsigned int) * 32);
 764                 else
 765                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 766                                sizeof(unsigned int) * 32);
 767                 fpregs32->pr_qcnt = 0;
 768                 fpregs32->pr_q_entrysize = 8;
 769                 memset(&fpregs32->pr_q[0], 0,
 770                        (sizeof(unsigned int) * 64));
 771                 if (fprs & FPRS_FEF) {
 772                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 773                         fpregs32->pr_en = 1;
 774                 } else {
 775                         fpregs32->pr_fsr = 0;
 776                         fpregs32->pr_en = 0;
 777                 }
 778         } else {
 779                 if(fprs & FPRS_DL)
 780                         memcpy(&fpregs->pr_regs[0], kfpregs,
 781                                sizeof(unsigned int) * 32);
 782                 else
 783                         memset(&fpregs->pr_regs[0], 0,
 784                                sizeof(unsigned int) * 32);
 785                 if(fprs & FPRS_DU)
 786                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 787                                sizeof(unsigned int) * 32);
 788                 else
 789                         memset(&fpregs->pr_regs[16], 0,
 790                                sizeof(unsigned int) * 32);
 791                 if(fprs & FPRS_FEF) {
 792                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 793                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 794                 } else {
 795                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 796                 }
 797                 fpregs->pr_fprs = fprs;
 798         }
 799         return 1;
 800 }
 801
 802 /*
 803  * sparc_execve() executes a new program after the asm stub has set
 804  * things up for us.  This should basically do what I want it to.
 805  */
 806 asmlinkage int sparc_execve(struct pt_regs *regs)
 807 {
 808         int error, base = 0;
 809         char *filename;
 810
 811         /* User register window flush is done by entry.S */
 812
 813         /* Check for indirect call. */
 814         if (regs->u_regs[UREG_G1] == 0)
 815                 base = 1;
 816
 817         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 818         error = PTR_ERR(filename);
 819         if (IS_ERR(filename))
 820                 goto out;
 821         error = do_execve(filename,
 822                           (char __user * __user *)
 823                           regs->u_regs[base + UREG_I1],
 824                           (char __user * __user *)
 825                           regs->u_regs[base + UREG_I2], regs);
 826         putname(filename);
 827         if (!error) {
 828                 fprs_write(0);
 829                 current_thread_info()->xfsr[0] = 0;
 830                 current_thread_info()->fpsaved[0] = 0;
 831                 regs->tstate &= ~TSTATE_PEF;
 832                 current->ptrace &= ~PT_DTRACE;
 833         }
 834 out:
 835         return error;
 836 }
 837
 838 unsigned long get_wchan(struct task_struct *task)
 839 {
 840         unsigned long pc, fp, bias = 0;
 841         unsigned long thread_info_base;
 842         struct reg_window *rw;
 843         unsigned long ret = 0;
 844         int count = 0;
 845
 846         if (!task || task == current ||
 847             task->state == TASK_RUNNING)
 848                 goto out;
 849
 850         thread_info_base = (unsigned long) task->thread_info;
 851         bias = STACK_BIAS;
 852         fp = task->thread_info->ksp + bias;
 853
 854         do {
 855                 /* Bogus frame pointer? */
 856                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
 857                     fp >= (thread_info_base + THREAD_SIZE))
 858                         break;
 859                 rw = (struct reg_window *) fp;
 860                 pc = rw->ins[7];
 861                 if (!in_sched_functions(pc)) {
 862                         ret = pc;
 863                         goto out;
 864                 }
 865                 fp = rw->ins[6] + bias;
 866         } while (++count < 16);
 867
 868 out:
 869         return ret;
 870 }